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Unlabelled research vial
Illustration: a blank vial with the compound’s name set on it, not a product photo or a test result.

Mitochondria and NAD+

SS-31

Also listed as Elamipretide, MTP-131

Mitochondria-targeted tetrapeptide (Szeto–Schiller peptide)

  • Cardiolipin
  • Inner mitochondrial membrane
Formula
C32H49N9O5
Molar mass
639.79 g/mol
CAS number
736992-21-5

Identity

What the molecule is, from its PubChem record. These are the figures a certificate of analysis should agree with.

Class
Mitochondria-targeted tetrapeptide (Szeto–Schiller peptide)
Sequence

H-D-Arg-Dmt-Lys-Phe-NH₂

  • Four residues with a C-terminal amide.
  • D-Arg is D-arginine; Dmt is 2′,6′-dimethyl-L-tyrosine.
Molecular formula
C32H49N9O5
Molar mass
639.79 g/mol
CAS number
736992-21-5

Checked against PubChem on 27 September 2026. Molar mass is calculated from the formula with standard atomic weights and agrees with PubChem’s published molecular weight. In sequences, H- marks a free N-terminus, -OH a free C-terminal acid and -NH₂ a C-terminal amide.

Research context

SS-31 is a synthetic tetrapeptide that alternates aromatic and basic residues, including 2′,6′-dimethyltyrosine. It concentrates in the inner mitochondrial membrane, where it is studied in isolated mitochondria and cell models for binding to cardiolipin and for changes in electron transport and reactive oxygen species production.

Research use only. Everything on Vialwise concerns research-grade material sold for laboratory and analytical use only. It is not a registered medicine, is not supplied for human or veterinary use, and nothing here is medical advice.

Storage and handling

  1. Store sealed lyophilised powder at −20 °C, dry and away from light.

  2. Let the vial reach room temperature before opening, so moisture doesn’t condense on the powder.

  3. Short and highly water-soluble, so it dissolves readily in sterile water.

  4. Split the solution into single-use aliquots and keep them frozen, so no portion goes through repeated freeze–thaw.

General laboratory practice for this class of material; your institution’s own procedures come first. To work out concentration and aliquot volumes from a vial’s mass, use the reconstitution calculator. For the reasoning behind each step, read storing lyophilised peptides.

Published lab reports

Lab reports for SS-31 at Au Peptide Labs Our store

The one supplier whose full report list we have.

Au Peptide Labs hasn’t published a lab report for SS-31 yet, so there is nothing here to check.

Other suppliers publish their reports on their own sites. Where each supplier publishes its COAs

Vialwise is published by APL Research Pty Ltd, which also runs Au Peptide Labs. Every supplier, ours included, is scored on the same published checklist. How we handle this

Any supplier

Check any supplier’s SS-31 COA

These checks take a few minutes and work the same on a report from any supplier, ours included. The walkthrough shows each one on a real Janoshik report.

How to verify a Janoshik COA
  1. Open it at the lab

    The report should load on the testing lab’s own website from the verify link or task number, not only as a PDF or screenshot from the supplier.

  2. Match the name

    The sample should be named SS-31, Elamipretide or MTP-131, or a clear equivalent. A different compound name means a different report.

  3. Match the mass

    If the report includes a mass-spectrometry result: a deconvoluted average-mass result should sit close to 639.79 g/mol; high-resolution reports give the slightly lower monoisotopic mass, and raw spectra show m/z for charged ions (mass ÷ charge). How HPLC and mass spec work.

  4. Match the vial

    The sample amount on the report should match the vial size you’re buying. A report on a different size or an older batch tells you less about the vial in front of you.

Related

Full library
  • Mitochondria and NAD+

    MOTS-c

    Mitochondrial-derived peptide (16 residues)

    C101H152N28O22S22174.59 g/mol

  • Mitochondria and NAD+

    NAD+

    Coenzyme (dinucleotide), not a peptide

    C21H27N7O14P2663.43 g/mol